Electrical condenser



April 13, 1937. J. E. LILIENFELD ELECTRICAL CONDENSER Filed Sept. 24, 1931 Vijcousflectroly'te Copper A 4 V \1 m 0 ,n u M 4 I Z /3 1 E? lllllllll] E.

INVENTOR (/01. /(/6 054? A a us/vrao ATTORNE iatented Apr. 13, 1937 I UNITED snares signor, hy mesne assignments, to The Magma vox tCompany, Fort Wayne, End, a corporation of Arizona Application Septeinher 2Q, 1931, Serial No. dlidfidd Z? @lainis.

The invention relates to electrical condensers,

more especially of the electrolytic type, the electrodes being separated by a highly viscous electrolyte and coiled or formed into a roll.

5 In condensers of this nature; the active film of the anode is frequently mechanically injured in the winding or rolling up operation, which results in a larger number of rejections, and reduces materially the efliciency of the finished condenser and also its life.

It is an object of the present invention to construct a condenserof this type in such a manner that the danger of any mechanical injury to the active layer is greatly reduced if not entirely obviated, more especially in the provision of an overlying protective inactive layer.

- A further object of the invention resides in the provision or a novel electrolyte of a highly viscous or more or less pasty nature which will further serve to protect the active film.

The present invention is a continuation in part of my prior applications, Serial No. 560,140 and No. 560,141, filed August 29, 1931.

i The nature of the invention, however, will best be understood when described in connection with the accompanying drawing, in which:

Fig. 1 is a fragmentary transverse section, on a greatly exaggerated and disproportionate scale, through a number of electrodes and separating electolyte.

Fig. 2 is a perspective view of a condenser roll.

Fig. 3 is vertical section, partly in elevation, of the roll encased in a suitable housing member for the same.

Referring to the drawing, l0 designates an anode and II a cathode of a series of alternately spaced electrodes separated by a highly viscous electrolyte l2 and with interposed retiform insulating material l3, such as cambric, permeated 40 by the said electrolyte. In addition to a novel electrolyte, the anodes l0 are of a novel nature, more especially with reference to the coating applied thereover. Heretofore, but a single coating, for example in the case of aluminum anodes, the oxide or coating formed in boric acid,

and on occasions to such an extent that the con-.

denser is rendered practically useless.

In the preparation of this anode, furthermore,

the forming 01' the same is to be effected prior to the assembly of the condenser electrodes, the viscous electrolyte being utilized merely to separate the electrodes and to afiord the electrolyte for operation of the condenser.

In accordance with the invention and as more particularly set forth in my aforesaid copending application Serial No. 560,141., the coating applied to the anode is of a loilaminate nature molecularly associated with the anode metal and of which the proximate layer M constitutes the active and dielectric film, while the outer or over lying layer it is inactive, of mechanically measuralole thickness, and permeable to OH ions in the presence of Water or aqueous vapor.

V lhis heavier overlying layer I15 afiords thus a substantial protective coating over the underlying layer of minute thickness to adequately protect the sane in the rolling up of the condenser elernent's. Moreover, it makes for advantages; electrically, e. g. higher breakdown voltage, the possihility of reducing power loss in the admixture of a conducting filler to the electrolyte, and as is more fully set forth in my aforesaid copending application, Serial No. 560,141.

The metal utilized for the anode is, of course, to he of a filming nature such as aluminum, tantalum, etc, and the film [Ml maybe the oxide thereof, as obtained by forming the anode in loorlc acid, while the overlyingfilm l5 may be the phosphate as obtained by forming in phosphoric acid. These films are applied in the man-1 her more particularly set forth in my said all pending application, Serial No. 580,141, and are the protective featrne, as well as adording a sub stantial separating medium. It is of a highly viscous nature and preieralolyof a conducting mass constituted, for example, loy a condensation product of an alcohol and an acid such as is more particularly set forth in my aforesaid copending application, Serial No. 560,1d0. As set forth, this electrolyte comprises a glycol (triethylene glycol), or compounds thereof, with a weal; mineral or organic acid, such as horic acid, the polymerization being efiected preferably in the presence of a catalyst, such as zinc chloride. In order to render this electrolyte plastic and give a very firm loody thereto, there may be suspended therein a suitable filler material such as a conducting dust (aluminum and copper dust, etc, or finely divided subdivided carbon as lamp lolaclr and activated charcoal), or an insulating dust such as diatoniaceous earth, regenerated or not regenerated cellulose dust, as well as a mixture of a conducting filler with m insulating filler.

The separated electrodes are rolled or coiled 5 in well-known manner to form a roll it, as indicated in Fig. 2 of the drawing; and, if desired, the roll may be housed within a suitable casing ll, leads being brought out from the respective electrodes to corresponding terminals I8 and I! on the cover 20 of the casing.

I claim:

1. An electrical condenser, comprising alternate electrodes separated by a highly viscous electrolyte and retiform material, the anodic electrode being preformed and having a bilaminate integral coating molecularly associated therewith and the proximate layer constituting the active and dielectric film and the overlying layer being inactive and permeable to OH ions in the presence of water or aqueous vapor, the whole being in coiled form.

2. An electrical condenser, comprising alternate electrodes separated by a highly viscous electrolyte and retiform material, the anodic electrode I being preformed and having a bilaminate integral coating molecularly associated therewith and the proximate layer constituting the active and dielectric film and the overlying layer being inactive and permeable to OH ions in the presence of water or aqueous vapor, the whole being coiled into a roll, and a casing for the roll provided with suitable terminals connected to the respective electrodes.

3. An electrical condenser, comprising alternate electrodes separated by a highly viscous electrolyte consisting of a reaction product of a glycol and boric acid and retiform material, the anodic electrode being of preformed aluminum and having a bilaminate integral coating molecularly associated therewith, and the proximate layer being an oxide of aluminum and the overlying layer a phosphate thereof, the whole being in coiled form.

4. An electrical condenser, comprising alternate a highly viscous electrolyte comprising a reaction product of a glycol with boric acid, the anodic electrode being preformed and having a bilaminate integral coating molecularly associated therewith and the proximate layer constituting the active and dielectric film and the overlying layer being inactive and permeable to OH ions in the presence of water or aqueous vapor, the whole being in coiled form.

6-. An electrical condenser, comprising alternate electrodes separated by a retiform material and a highly viscous electrolyte comprising a condensation product of an alcohol and an acid and mixed with a filler, the anodic electrode being preformed and having a bilaminate integral coating molecularly associated therewith and the proximate layer constituting the active and dielectric film and the overlying layer being inactive and permeable to OH ions in the presence of water or aqueous vapor, the whole being in coiled form.

7. An electrical condenser, comprising alternate I JULIUS EDGAR LILIENFELD. 

